CN109824683B

CN109824683B - Rhodamine B Hg based on 2-thiopheneacetyl chloride2+Preparation and application of fluorescent sensor

Info

Publication number: CN109824683B
Application number: CN201910259224.7A
Authority: CN
Inventors: 阚春; 邵晓涛; 宋钒
Original assignee: Nanjing Forestry University
Current assignee: Nanjing Forestry University
Priority date: 2019-04-01
Filing date: 2019-04-01
Publication date: 2022-02-11
Anticipated expiration: 2039-04-01
Also published as: CN109824683A

Abstract

The rhodamine B fluorescent sensor provided by the invention has the advantages of strong selectivity, quick response time and high sensitivity when being applied to a water phase²⁺The method of (1). Measuring the intensity change of the characteristic peak of the rhodamine B probe in the water phase by adopting a fluorescence spectrophotometer and an ultraviolet-visible spectrophotometer to further determine Hg²⁺Is present. The invention takes rhodamine B (RhodanmineB) as a raw material to synthesize a novel fluorescent sensor based on 2-thiophene acetyl chloride. The invention provides that the fluorescence sensor is applied to Hg²⁺Application in detection, and finds application in Hg²⁺Has good detection effect, and compared with the prior art, the invention has the advantages of low development cost, easy realization and simple and convenient operation, and can be applied to Hg²⁺Has bright application prospect in the aspect of detection.

Description

Rhodamine B Hg based on 2-thiopheneacetyl chloride2+Preparation and application of fluorescent sensor

Technical Field

The invention belongs to the field of biochemistry, and particularly relates to rhodamine B Hg based on 2-thiopheneacetyl chloride²⁺Preparation and application of a fluorescence sensor.

Background

Mercury is typically a rare heavy metal and is the only metal that can exist in liquid form at ambient temperature and pressure. Mercury is a naturally occurring element that is widely found in nature in various environmental media and food chains (especially fish) primarily in the form of simple substances and ions. Under the action of microorganisms, inorganic mercury such as metallic mercury and divalent mercury ions can be converted into methyl mercury or dimethyl mercury. Hg is a mercury vapor²⁺Is a very toxic chemical substance that readily penetrates the cell membranes in the skin and respiratory tract, and subsequently causes irreversible damage to the human internal organs, central nervous system, digestive system, respiratory system and blood. In addition, oneOnce bioabsorbed, it deposits in the brain, liver and other organs, causing chronic poisoning, damage to vital organs, and even death. Hg is a mercury vapor²⁺The ligand containing S atom has strong affinity to human body, and can combine with some groups (such as sulfhydryl) in human body protein, so that many metabolisms in cell are affected, and the growth and function of cell are affected. In human, trace mercury may cause mercury poisoning and other serious diseases, including headache, Parkinson's disease and water deficiency. Therefore, a novel Hg which is low in cost, easy to realize, quick in response and suitable for natural environment and biological system is developed²⁺The detection means is very important.

Currently, widely used detection techniques mainly include elemental mercury atomic absorption/emission spectroscopy, X-ray fluorescence spectroscopy, inductively coupled plasma mass spectrometry, nuclear magnetic resonance, colorimetric and electrochemical methods. However, most of these methods are limited by short plates, such as cumbersome steps or expensive instruments, which limits their further development and application. Another disadvantage of these methods is the high energy excitation, which can severely damage the biological sample. Therefore, a novel mercury ion (Hg) suitable for natural environment and biological system has been developed²⁺) Detection means are very important, especially the development of some low-cost and quick-response inspection means. In recent years, molecular probes for detecting heavy metal ions by using an optical means have attracted much attention by virtue of the advantages of low development cost, easy realization, fast response, suitability for natural environments and biological systems, simple and convenient operation, low detection limit, high sensitivity and the like. Therefore, it is difficult to develop a molecular probe having excellent properties in all respects.

Rhodamine B has excellent photophysical properties such as good solubility, high quantum yield, large molar absorption coefficient, long excitation wavelength, extension of emission wavelength to a visible region and the like, is a typical fluorescent group, and can be used for constructing a fluorescent chemical sensor for detecting various analytes. Fluorescent probes based on rhodamine derivatives for detecting metal ions, anions, thiols, etc. were developed in succession.

Disclosure of Invention

The invention aims to provide 2-thiopheneacetyl chloride-based rhodamine B Hg²⁺Preparation and application of the fluorescence sensor.

The technical solution for realizing the purpose of the invention is as follows:

rhodamine B Hg based on 2-thiopheneacetyl chloride²⁺A fluorescence sensor RBST, the structure of which is as follows:

rhodamine B Hg based on 2-thiopheneacetyl chloride in the invention²⁺The preparation method of the fluorescence sensor RBST comprises the following steps:

compound 1(193.6mg, 0.4mmol) was added to 30mL of anhydrous dichloromethane in a 50mL round bottom flask, stirred to complete dissolution, followed by dropwise addition of 2-thiopheneacetyl chloride (50uL, 0.4mmol) and triethylamine (56uL, 0.6mmol), stirred at room temperature for 4h, and the progress of the reaction was monitored by TLC thin layer chromatography. After the reaction was completed, the solvent was removed under reduced pressure, and then 30mL of toluene was added to the flask, and after stirring to completely dissolve, Lawson's reagent (161.8mg, 0.4mmol) was added and refluxed at 80 ℃ for 24 hours, and progress of the reaction was monitored by TLC thin layer chromatography. After the reaction is complete, saturated K is added₂CO₃And treating the solution for 2-3 h. The solution changes from purple to yellow and then CH is used₂Cl₂Saturated brine extraction three times, reverse extraction one time, drying the organic phase with anhydrous magnesium sulfate, filtering, distilling under reduced pressure to remove solvent, and using CH₂Cl₂Petroleum ether (3: 2, v/v) is used as eluent, and the compound is quickly separated and extracted by a silica gel column. Obtaining orange yellow powder which is the Hg²⁺A fluorescence sensor. Wherein the structure of compound 2 is as follows:

in the present invention, the molar ratio of compound 2 to 2-thiopheneacetyl chloride is 1: 1.

In the present invention, the molar ratio of compound 2 to Lawson's reagent is 1: 1.

In the invention, the eluent adopted by the silica gel column separation and purification is CH₂Cl₂Petroleum ether is 3: 2.

In the present invention, the reaction time of compound 2 with 2-thiopheneacetyl chloride was 4 hours.

In the invention, the reaction time is 24 hours after the Lawson reagent is added.

The 2-thiopheneacetyl chloride-based rhodamine B fluorescence sensor RBST is used for detecting Hg²⁺。

Compared with the prior art, the invention has the following remarkable advantages: (1) the invention synthesizes Hg by using rhodamine as a main body²⁺The fluorescence sensor RBST has the advantages of strong selectivity, low detection limit, high sensitivity, reversibility, larger molar absorption coefficient, high fluorescence quantum yield, excellent spectral performance, simple structure, easy modification and the like. (2) The method has the advantages of low cost of the selected raw materials, simple synthesis steps, few post-treatment steps and easy realization of large-scale production. (3) The invention adopts the condensation reaction of 2-thiopheneacetyl chloride and primary amine for vulcanization, and has the advantages of simple synthesis method, mild reaction conditions and higher yield. (4) The fluorescence sensor can selectively detect Hg²⁺The method has the advantages of change, high sensitivity and good application prospect in various fields such as natural environment, biological system and the like.

Drawings

FIG. 1 shows Compound 1 of the present invention¹H NMR。

FIG. 2 shows Compound 2 of the present invention¹H NMR。

FIG. 3 shows a compound fluorescence sensor RBST of the present invention¹H NMR。

FIG. 4 shows fluorescence selectivity of the compound fluorescence sensor RBST of the present invention.

FIG. 5 is a graph showing the UV selectivity of a compound fluorescence sensor RBST of the present invention.

Detailed Description

Synthesis of (I) fluorescence sensor RBST

The invention provides a target product RBST in Hg²⁺Application in detection, and finds application in Hg²⁺Has good detection effect. The synthetic route of the invention is as follows:

(II) fluorescence Property test

Mixing Fe³⁺，Al³⁺，Ba²⁺，Cd²⁺，Ca²⁺，Co²⁺，Cr³⁺，Cu²⁺，Hg²⁺，K⁺，Mn²⁺，Mg²⁺，Ni⁺，Na²⁺，Pb²⁺，Zn²⁺Adding different heavy metal ions into the solution of the compound RBST, and carrying out fluorescence selection performance test.

(III) ultraviolet testing

Mixing Fe³⁺，Al³⁺，Ba²⁺，Cd²⁺，Ca²⁺，Co²⁺，Cr³⁺，Cu²⁺，Hg²⁺，K⁺，Mn²⁺，Mg²⁺，Ni⁺，Na²⁺，Pb²⁺， Zn²⁺Adding different heavy metal ions into the solution of the compound RBST, and carrying out ultraviolet selection performance test.

The invention is described in further detail below with reference to the figures and specific examples.

Example 1

Synthesis of fluorescent sensor

1. Synthesis of Compound 1

A100 mL round-bottomed flask was charged with rhodamine B (960mg, 2mmol) and 40mL absolute ethanol, followed by slow dropwise addition of ethylenediamine (1.3mL, 20mmol) to the above solution. After the dropwise addition, the reaction temperature was raised to 80 ℃ and the reaction was carried out under reflux for 10 hours. After completion of the reaction, ethanol was removed by rotary concentration. Then using CH at room temperature₂Cl₂Saturated saline solution extraction three times, reverse extraction once. The organic phase was dried over anhydrous magnesium sulfate, filtered, and distilled under reduced pressure to remove the solventSolvent, extract, and isolate by silica gel column to give a pale yellow solid (887.7mg, 92.8%). Compound 1¹H NMR is shown in FIG. 1.

2. Synthesis of Compound 2

Compound 1(193.6mg, 0.4mmol) was added to 30mL of anhydrous dichloromethane in a 50mL round bottom flask, stirred to complete dissolution, followed by dropwise addition of 2-thiopheneacetyl chloride (50uL, 0.4mmol) and triethylamine (56uL, 0.6mmol), stirred at room temperature for 4h, and the progress of the reaction was monitored by TLC thin layer chromatography. Compound 2¹H NMR is shown in FIG. 2.

2. Synthesis of Compound RBST

Compound 2 was added to 30mL of toluene in a 50mL round bottom flask, stirred to dissolve completely, Lawson's reagent (161.8mg, 0.4mmol) was added and warmed to 80 deg.C for reflux 24h, and the progress of the reaction was monitored by TLC thin layer chromatography. After the reaction is complete, saturated K is added₂CO₃And treating the solution for 2-3 h. The solution changes from purple to yellow and then CH is used₂Cl₂Saturated brine extraction three times, reverse extraction one time, drying the organic phase with anhydrous magnesium sulfate, filtering, distilling under reduced pressure to remove solvent, and using CH₂Cl₂Petroleum ether (3: 2, v/v) is used as eluent, and the compound is quickly separated and extracted by a silica gel column. Orange-yellow solid (164mg, 64%) was obtained as the Hg²⁺A fluorescence sensor RBST. Of compound RBST¹H NMR is shown in FIG. 3.

Example 2

Fluorescence selection Performance test

The fluorescence sensor RBST has good solubility in ethanol, and the compound RBST can be dissolved in EtOH/H through verification₂400mL of this solution was prepared as a stock solution in O (2: 1, v/v) mixture.

Accurate configuration of fluorescent sensor RBST of 1 × 10^-3mol/LEtOH/H₂O mixed solution (2: 1, v/v), CdCl₂·2.5H₂O， CuCl₂·2H₂O，AlCl₃，KNO₃，FeCl₃·6H₂O，HgCl₂，NiCl₂·6H₂O，MgCl₂·6H2O，NaCl，ZnCl₂， CrCl₃·6H₂O，Ba(NO₃)₂，MnCl₂·4H₂O，CoCl₂·6H₂O，CaCl₂，PbCl₂The concentration is 5X 10^- ³mol/L aqueous solution, and EtOH/H₂O (2: 1, v/v) solution.

Fluorescence selectivity experiment as shown in fig. 4, 3mL of stock solution was placed in a liquid pool, 60uL of fluorescence sensor RBST was added, the initial fluorescence intensity value was measured, then 60uL of each cation was added separately, and the fluorescence intensity at the time of stabilization was measured. As can be seen from the observation of FIG. 4, the compound RBST is responsible for Hg²⁺Has obvious response effect and the fluorescence intensity reaches the maximum value at 582nm, namely the compound RBST has the maximum value to Hg²⁺Has good selectivity.

Example 3

Ultraviolet selection Performance test

Accurate configuration of fluorescent sensor RBST of 1 × 10^-3mol/L EtOH/H₂O mixed solution (2: 1, v/v), CdCl₂·2.5H₂O，CuCl₂·2H₂O，AlCl₃，KNO₃，FeCl₃·6H₂O，HgCl₂，NiCl₂·6H₂O，MgCl₂·6H2O， NaCl，ZnCl₂，CrCl₃·6H₂O，Ba(NO₃)₂，MnCl₂·4H₂O，CoCl₂·6H₂O，CaCl₂，PbCl₂The concentration is 5X 10^- ³mol/L aqueous solution, and EtOH/H₂O (2: 1, v/v) solution.

Ultraviolet selectivity experiments as shown in fig. 5, 3mL of stock solution was placed in a liquid cell, 60uL of a fluorescence sensor RBST was added, initial absorbance was measured, then 60uL of each cation was added separately, and absorbance at steady state was measured. As can be seen from the observation of FIG. 5, the compound RBST is responsible for Hg²⁺Ming dynastyThe response effect is obvious, a new peak appears at 558nm, namely the compound RBST is used for Hg²⁺Has good selectivity.

Claims

1. Rhodamine B Hg based on 2-thiopheneacetyl chloride²⁺A fluorescence sensor having the following structure

2. Rhodamine B Hg based on 2-thiopheneacetyl chloride²⁺The preparation method of the fluorescence sensor comprises the following steps:

193.6mg of compound 1 was added to 30mL of anhydrous dichloromethane in a 50mL round bottom flask, stirred to complete dissolution, followed by dropwise addition of 50uL of 2-thiopheneacetyl chloride and 56uL of triethylamine, stirred at room temperature for 4h, and the progress of the reaction was monitored by TLC thin layer chromatography; after the reaction is finished, removing the solvent under reduced pressure, then adding 30mL of toluene into a flask, stirring until the toluene is completely dissolved, adding 161.8mg of Lawson reagent, refluxing at 80 ℃ for 24h, and monitoring the reaction process by TLC thin-layer chromatography; after the reaction is complete, saturated K is added₂CO₃Treating the solution for 2-3 h, and using CH after the solution changes from purple to yellow₂Cl₂Saturated brine extraction three times, reverse extraction one time, drying the organic phase with anhydrous magnesium sulfate, filtering, distilling under reduced pressure to remove solvent, and using CH₂Cl₂Petroleum ether is used as eluent, and compounds are rapidly separated and extracted through a silica gel column to obtain orange yellow powder, namely 2-thiopheneacetyl chloride-based rhodamine B Hg in claim 1²⁺A fluorescent sensor; wherein the structure of compound 1 is as follows

3. Rhodamine as claimed in claim 2 based on 2-thiopheneacetyl chlorideClass B Hg²⁺The preparation method of the fluorescence sensor is characterized in that the molar ratio of the compound 1 to the 2-thiophene acetyl chloride is 1: 1.

4. 2-thiopheneacetylchloride-based rhodamine class B Hg as claimed in claim 2²⁺The preparation method of the fluorescence sensor is characterized in that the eluent adopted by the silica gel column separation is CH₂Cl₂Petroleum ether, the volume ratio of the two is 3: 2.

5. 2-thiopheneacetylchloride-based rhodamine class B Hg as described in claim 1²⁺Use of a fluorescence sensor, characterized in that: 2-thiopheneacetylchloride-based rhodamine class B Hg as described in claim 1²⁺Fluorescent sensor for detecting Hg in water phase²⁺。